| TCE offers a user-level multithreading, which is advantages when efficiency is concerned, but possesses also a drawback -- a potentially blocking I/O operation will cause blocking the whole process, instead of blocking only the thread that issued that I/O request. |
| To cope with this problem, TCE translates blocking I/O calls into non-blocking ones. A thread that requests such an operation is then blocked (by the scheduler) until the underlying Operating System signals that the non-blocking operation has completed. |
| However, the presented solution is not general enough. On some Operating Systems certain I/O system calls don't have non-blocking (asynchronous) variations. Fortunately, all relevant OSs on workstations and MIMD parallel machines provide non-blocking interfaces for accessing terminals and network devices. |
| This is why programs using TCE should always use TCE calls to interact with the keyboard or the network. |
